Time-limit indicator.



H; R. POPE.

TIME LIMIT INDICATOR.

APPLICATION FILED maas, |916.

Patented Sept. 19, 1916.

2 SHEETS-SHEET l.

FIG.1.

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H. R. PUPE.

TIME LIMIT INDICATOR.

APPLlcmoN FILED M1128, 1916.

Patented sept. 19,1916.

2 SHEETS-SHEET 2.

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INVENTUR 2 @M A TTOHNE Y 55 vcated in the central office, in proximityto UNITED STATES PATENT OFFICE.

HENRY R. POPE, OF FRANKLIN, PENNSYLVANIA.

TIME-LIMIT INDICATOR.

' To all whom t may concern:

vao

Be it known that I, HENRY R. POPE, citizen of the United States,residing at Franklin, in the county of .Venango and State ofPennsylvania, have invented certain new and useful Improvements inTime-Limit Indicators, of which the'following is a specification.

My invention relatesto an improved timelimit indicator, `which isadapted for various purposes, but isv here shown and described as beingapplied to telephone service, for which it is especially adapted.

'The' object, construction and utility of my improvedtime-limitindicator, when applied to the use above stated, are hereinset forth with sufficient clearness to enable those skilled -in the artof telephone construction and operation, to make and use 'the same.

In .the operation of nearly all telephone systems, t-is customary toimpose a specific time limit per message for'the' use vof certain lines,and in such cases it is desirable to have some -device which willautomatically apprise the `operator when `such limit of time has beenreached, so that the `line may be disconnected.

It is, therefore,'the object of this invention to provide-a device whichmay be in- 'terposedin the lines of a telephone system,

which will be automatically set in operation by the connection of thelines for use,that is when the operator inserts the plug in the jack-andwhich will, at the expiration of a certain pre-determined limit of time,cause either an audible or visual indication to be set up, and wherebythe operator will be informed that the line hasbeen in use for theallotted period of time.

In the drawings which form a part hereof, I have shown a preferred formand a modied form of construction whereby I attain lsaid object.

g The various figures of said drawings are as follows:

Figure l is a transverse section of said device on line 1-1 of Fig. 2.`Fig. 2 is a front elevation of same. Fig. 3 is a detail. Figs. 4v and 5show a modified form of construction. Fig. 6'is a diagram illustratingone. wayin which my device may be connected into a telephone system.

Theconstruction shown in Figs. l, 2, 3 and v6 is substantially asfollows: Within one lof the circuits of aI telephone, and lo- Speccationof Letters Patent.

Patented Sept. l19, 1916.

the operators position, is interposed any suitable indicative devicewhich is adapted to manifest either an audible or a visual signal, andwhich is shown in the drawings as a lamp l, Fig. 6. Also in the signalcircuit is interposed a suitable automatic switch 2, which is adapted,upon making suitable contact with a coperating element, to close saidcircuit, whereby the indicative device is energized and caused toproduce the desired signal. Said element 2, which I term the traveler,or traveling terminal, is shown in elevation in Fig. 3, is adapted andarranged to close the 'signal circuit at the expiration of the limit oftime which is prescribed for the use of the respective line with whichvit is associated, and, by such closing of said circuit to energize theindicative means, whereby the loperator is informed that the line may bedisconnected. The mechanism whereby said traveling terminal is actuatedcomprises a continuouslyrevolving shaft 3, which revolves in the`direction indicated by the arrow. To said shaft 3 is connected asuitable train of clockwork shown especially in Fig. A1, the gear 4C ofwhich is operably or rigidly mounted upon the shaft 3. Said train ofclock work is so constructed that said shaft 3 revolves at al slow rateof speed,preferably about the same speed as that of thefshaft upon whichthe hour-hand of an ordinary clock is mounted. The traveling terminal 2is loosely mounted upon said shaft 3 and is magnetically retained in itsnormal, opencircuit position as shown in Fig. 1 by means of the magnet5. Said terminal is provided with a resilient friction element 6, theupper end of which is secured to said traveler in any suitable way,andthe lower end thereof bears against said shaft and the amount offriction which is caused between said element 6 and said shaft 3 isregulated by means of the screw 7 such friction is never suflicient,however, to overcome the magnetic attraction of the coil 5, when saidcoil or magnet is energized. LOne pole of any suitable source ofelectrical current is connected, by means of a suitable conductor, tosaid shaft 3, which is grounded. In proximity to the upper, free endofsaid traveling electrode 2 is located an adjustableterminal 8, to whichthe other pole of said electrica-l source is connected.

The indicative means l, may, in a telephone system, be interposed ineither the line circuit or in the cord circuit, but it is here shown asbeing interposed in the line circuit and its co-nnections are such that,when the operator inserts the plugs in the jack to place the line inservice, the magnet 5 is thereby automatically denergized, which causesit to release said terminal 2, which thereupon becomes free to move withsaid shaft 3 upon which it is mounted, and it does so move until theupper end thereof comes into contact with the adjacent end of theterminal 8; this co-mpletes the signal circuit, energizes the indicativedevice, and informs the operator that the prescribed limit of time haselapsed.

By the longitudinal adjustability of the terminal 8, whereby theintervening space between the contact point of same and the terminal 2may be varied, the time limit may be varied, either shortened orlengthened, as desired.

When the line is disconnected, the removal of the plug from the jackautomatically restablishes a current through the magnet 5, and thetraveler or terminal 2 is drawn by the resulting magnetic attraction toits normal, open-circuit position.

Several terminals 2 may be mounted upon the same shaft 3, as shown inFig. 2, and when this is done, it may be found to be desirable to mounta drum 9 upon said shaft, about which, a weight-cord 10 may be wound,having a weight 11 attached thereto, the action of which will be toassist the clock work to overcome the frictional resistance of theterminals 2 when they are in a stationary condition, at either open orclosed circuit.

In Figs. 4 and 5 I have shown a. modified form of construction forholding and releasing the terminal 2. This comprises a solenoid 12, theplungers 13 of which normally, and when the coil of said solenoid is notenergized, rests upon the foot 14 of said terminal and retains the samein the position shown in Fig. 4. When the solenoid becomes energized, byplacing the plug within the jack, the plunger 13 is magnetically raisedto and retained in the position shown in Fig. 5 and-this will permitsaid terminal 2 to move with the shaft 8 upon which it is mounted, andit does so move until the upper end comes into contact with the terminal8, thereby closing the signal circuit.

When the operator removes the plug from the jack to disconnect the linewith which the signal coperates, this also automatically cuts out thesolenoid, and denergizes the same, which permits the plunger 13 to fallupon the foot 14 which restores the terminal to its open-circuitposition. This construction will require a slight re-arrangement of thesignal circuit incident to energizing the release device, instead ofrenergizing same to cause its release of the terminal, but such changesas this may require, will be readily perceived and made by those skilledin the art of electrical construction and wiring.

From the foregoing description, it may be readily understood that thisindicator is not a busy indicator which is in the indicative conditionthroughout the time that the line with which it is associated, is busy,but on the contrary, it becomes in the indicative condition only at theinstant when the limit of time has been reached, thereby apprising theoperator at precisely the time when the line should be disconnected, inorder that the use of said line may not exceed the prescribed limit oftime.

As previously stated, in Fig. 6 I have shown the indicative device 1 asbeing interposed in the line circuit, but I do not wish to be understoodas confining the 1ocation of same to such position, as it could withequal facility be interposed in the cord circuit, and, as a matter offact, when many lines are to be equipped with my device, it will bepreferable, for various reasons, readily apparent to those skilled inthe art, to interpose said indicative device in the cord circuit; such atransposition would necessitate a slight change in the wiring and someof the accessories, but these changes will be readily perceived and madeby any skilled electrician.

There are many other purposes for which my improved time-limit indicatormay be used in addition to telephone service, and, in fact it may beadvantageously employed wherever certain pre-determined periods of 'timeare to be observed, such as photographic exposure, printing anddevelopment, recitation periods in schools, etc.

I claim the following:

A time-limit indicator, comprising, in combination, a source ofelectrical current, a conductor connected to one of the poles of saidsource, a conductor connected to the other pole of said source, astationary terminal to which one of said conductors is connected, amovable terminal to which the other of said conductors is connected,said movable terminal being arranged to be moved into contact with saidstationary terminal so as to form an electrical circuit, acontinuously-moving element by which said movable electrode is carriedand by which it is adapted to be moved, at a certain predetermined rateof speed from a normal, open-circuit position to said closed-circuitposition, releasable means adapted to detain said movable terminal atits open-circuit position and to release the same as required whereby itbecomes free to be moved by said continuously-moving element into saidclosed-circuit position, the travel of said movable terminal being suchas to define a pre-determined interval of time, means adapted to varysaid interval as desired, an In testimony whereof I afx my signatureindicative device interposed in one of said in presence of twoWitnesses.

conductors adapted to indicate the closing HENRY R. POPE. of saidcircuit, and means adapted to re- Witnesses:

store said movable terminal to its normal, ELIsHA W. CREsWELL,

open-circuit position. MARGARET MARTIN.

Copies of this patent may be obtained for five cents each, byaddressing` the Commissioner of latents, Washington, D. G.

